Fossil group

Claraia bivalves

Molluscs · Early Triassic

A thin, flat, almost disc-like bivalve that carpeted sea floors worldwide in the Early Triassic. As one of the first animals to flourish after the end-Permian mass extinction — Earth’s greatest — it is a hallmark of the recovery interval.

A broad fossil group rather than a single taxon — the units below record it among their fauna or flora.